Grab attachment for tractor loader



Jan. 4, 1966 w. KAMPERT ETAL 3,227,297

GRAB ATTACHMENT FOR TRACTOR LOADER 2 Sheets-Sheet 1 Filed Sept. 23, 1963 JDMENTORS jz'Z/i fi ur ne/zijicficuzdk z jnjflne'unam/ 1956 K. w. KAMPERT ETAL 3,

GRAB ATTACHMENT FOR TRACTOR LOADER Filed Sept. 25, 1963 2 Sheets-Sheet 2 ll 41 gig 2 g6 46' INVENTORS. 1/ JZwz Qe/u United States Patent 3,227,297 GRAB ATTACHMENT FOR TRACTOR LOADER Keith W. Kampert, Libertyville, and Richard F. Zimmerman, Waukegan, Ill., assignors to The Frank G. Hough Co., a corporation of Illinois Filed Sept. 23, 1963, Ser. No. 310,810 6 Claims. (Cl. 214-147) This invention relates to tractor loaders and more particularly to an attachment connected to a tractor loader for handling cylindrical objects such as pipe, etc.

It is the object of the present invention to provide an improved tractor loader having an attachment particularly adapted for handling of cylindrical objects such as pipes, tubes, logs, poles, etc. The pipe-handling attachment of the present loader is particularly effective and is quickly adapted to the handling of different diameter objects and by virtue of its novel construction is adapted to securely grab, raise, lower and release cylindrical objects to be handled. The elements of the attachment are constructed so as to give added stability to the loader during the roll back operation, and in the maximum roll back position the alignment of the weight of the load over the lower grab member of the attachment will afford an advantage in relieving strain from the upper grab arm. Furthermore, this positioning will place the major weight of the load on the boom member, which by reason of its greater size and strength is better adapted to carry the weight of the load.

Other objects will become more readily apparent from a reading of the description when examined in connee tion with the accompanying sheets of drawings.

In the drawings:

FIGURE 1 is a side elevational view of the forward portion of a tractor loader having an improved material handling tong attachment connected thereto;

FIGURE 2 is a cross sectional view taken along the line 2-2 of FIGURE 1;

FIGURE 3 is a side elevational view of a modified material-handling tong attachment attached to the forward end of a tractor loader;

FIGURE 4 is a detail perspective view of a grab shoe;

FIGURE 5 is a schematic view of a hydraulic system; and

FIGURE 6 is a cross sectional view taken substantially along the line 66 of FIGURE 3.

Referring now particularly to FIGURES 1 and 2, a tractor loader 10 (of which onlythe front portion is disclosed) is provided with front ground wheels ll supporting a frame 12. The frame 12 has supported thereon an operators station 13. A pair of transversely spaced boom arms 15 have their rearward ends pivotally connected as indicated at 16 to brackets 17. A pair of hydraulic rams 14 are pivotally secured as indicated at 18 to the frame 12, the said rams 14 including extensible rods 19 pivotally connected as indicated at 20 to the boom arms 15. t i

A control linkage is designated by the reference character 21 and comprises a ram 22 pivoted as indicated at 23 to a bracket 23' supported on the frame 12 of the tractor loader 10. The ram 22 includes a piston rod 24 pivotally connected to an arm 25 as indicated at 26. The arm 25 is centrally connected to a cross tube 27 in turn pivoted on a shaft 28 extending transversely of the boom arms .15 and being secured thereto. The tubular member 27 has connected thereto at oppositeends downwardly depending fork members 29 (only one of which is shown). The fork members 29 in turn have pivotally connected thereto links 30. 3 3

A load-handling attachment is generally designated at 31 and comprises a grab member 32 having a semi-cylindrical or arcuate front surface 33 extending transversely 'with respect to the tractor loader 10. The arcuate surface 33 is formed by a plate of steel or similar material having at its opposite ends semi-cylindrical flanges 35. The arcuate back portion of the plate is designated at 34. As best shown in FIGURE 2, a pair of brackets are mounted on the back portion 34, these brackets comprising transversely spaced plates 36 suitably connected to the back portion 34. The grab member 32 is provided with openings 37 positioned on the member 32 immediately adjacent the plates 36. Each of the boom arms 15 has its forward end connected to each outermost plate 36 by means of a pivot pin 38, as best shown in FIGURES 1 and 2. The pivot pin 38 is also supported on rearward extensions 39 of each flange 35. A pair of grab arms 41 are disposed between each set of plates 36 as best shown in FIGURES 1 and 2.

The grab arms 41 are pivotally connected as indicated at 42 to the plates 36 and each set of grab arms 41 includes a transversely extending cylindrical grab surface member 43 suitably connected to each set of the arms 41. The arcuate surface 33 and the arcuate surfaces 43, when together, as shown in FIGURE 1, form a substantially continuous cylindrical surface. Rams 44 are connected between each of the sets of plates 36 and are pivoted as indicated at 45. Each ram 44 comprises a piston rod 46 pivoted as indicated at 47 to ends of the grab arms 41 for pivoting the same about the pivot 42. The links 30 are pivoted as indicated at 48 to the downwardly extending fork members 29 and have their other ends also pivoted as indicated at 49 to the plates 36.

In the modification shown in FIGURES 3, 4, and 6 a U-shaped shoe is generally designated by the reference character 50. The shoe 50 comprises a pair of spaced plates 51 having outwardly projecting ears 52 having holes therethrough, as indicated at 53. The plates 51 are interconnected by a transverse arcuate member 53'. A pair of rubber strips 54, as best shown in FIGURES 3 and 4, are connected to the plates 51 and project outwardly with respect thereto. The rubber strips 54 are suitably connected to the sides of the plates 51 by means of angles 55 and bolt-and-nut assemblies 56. Two of the shoes 50 are attached to the grab member 32. As shown in FIGURE 3, the ears 53 project through the openings 37 and they are connected to be retained on the grab member 34 by means [of bolt-and-nut fasteners indicated by the reference 56.

A :shoe indicated by reference character 57 is connected to each of the grab arms 51. The shoe 57 is best shown in FIGURE 6 and comprises a pair of plates 58 connected by a transversely extending plate 58'. Rubber strips 59 are suitably connected to the plates 58 by means of angle members 60 and bolt and nut assemblies 61 so that the rubber :strips 59 project outwardly with respect to the shoe 57. A shoe 57 is connected to each of the grab arms 41 by means of a single pivot bolt 62 extending through the grab arms 41.

Referring now to FIGURE 5, a hydraulic system for actuating the rams 14, 22 and 44 is disclosed. The hydraulic system comprises a conventional open center valve 63 having a movable spool valve 64. The spool valve 64 is adapted to function to supply fluid under pressure alternately to conduits 65 and 66 communicating respectiveadapted to alternately provide for fluid under pressure through conduits 71 and 72 connected respectively to opposite ends of the rams 44. A fluid reservoir is indicated at 73 and a pump 74 communicates with the reservoir 73 to supply fluid under pressure through the valve 63. A return line 76 communicates with the valve 63 and delivers fluid back to the reservoir 73. The rams 14, 22 and 44 are all of the two-way operating type. When pressure is supplied to the conduits for delivery to one end of the rams, the conduits at the other end of the rams are communicating with the conduit-76 returning to reservoir.

In the operation, the rams 14 are'extended for raising the boom armslS and for lowering the same. The loadhandling device 41 is quickly attached to the boom arms by the pivot members 38 and likewise the links 30 are quickly attachable by means of the pivot means 49 to the plates 36. The attachment device is particularly useful for handling cylindrical objects such as pipes, poles, etc. By retracting the piston 46 into the ram 44, the grab arms 41 are pivoted to an open position and the device 31 is placed in engagement with a cylindrical object A to be :moved as indicated in FIGURE 1. The rods 46 of the The operator may noW choose to raise the cylindrical member A into a dumping position whereupon extension of the piston rods 19 is eflectedwith respect to the rams 14. As the boom arms 15 are pivoted about the pivot members, the geometry to the control linkage 21 is such that the grab member 32 is pivoted in a counterclockwise direction about the pivots 38 to the extent shown in dotted lines in FIGURE 1. In this position, the maximum height has been achieved, and the load-handling device 31 is in position for dumping the cylindrical member A or discharging the same to the desired location. By now retracting the piston rod 24 into the ram 22, the grab member 32 may be pivoted in a clockwise direction about the pivot points 38 and upon retraction of the rod 46 into the ram 44, the grab members'41 are opened permitting discharge of the cylindrical member being carried.

It is also apparent in the broken line position of FIG- URE 1 that the grab member 32 has been automatically positioned so that the major load or weight of the cylin drical object is supported on the grab member and since the major portion of the grab member 32 is disposed underneath the cylindrical member, very little weight is supported on the grab arms 41 thus permitting the cylindrical ember to be safely moved by the vehicle in the raised position from one location to another.

The relationship of the attachment elements to the loader as shown in the broken line view of FIGURE 1 produces the maximum roll back position for the grab member and arm. It is at this maximum'roll back 'position that the center of the load will be in vertical alignment with pivot point 38, and thus the major 'weight of the load will be transmitted through the grab member 32 directly to the boom arms 15. Because stability of the loader during operation is improved in direct relation- :ship to the amount in which the load is moved toward the center of the loader, then at this maximum roll back position the optimum combination of loader stability and weight distribution to the boom arm is obtained.

If it is desired to move cylindrical members having a smaller outer diameter than the inner'diameter of the grab arms and grab member shown in FIGURE '1, it is a simple matter to secure the shoes 50 to the grab member 32 by placing the ears 53 through the openings 37 and then securing them by means or ordinary bolt and nut assemblies 56'. Also the shoes 57 are quickly placed in position by the pivotal connecting members 62. Thus, the type of load-handling device herein indicated may be designed to take the largest diameter cylindrical member to be transported and individual grab shoes are readily attached for accommodating the handling device to cylindrical members of lesser diameter.

Thus, it can be seen that the objects of the invention have been fully achieved and that an improved tractor loader and load-handling device has been disclosed.

It must be understood that changes and modifications may be made without departing from the spirit of the invention as disclosed or from the scope thereof defined in the appended claims.

What is claimed is:

1. In a tractor loader including a pair of boom arms, each having one end pivotally connected to opposite sides of said loader, a first extensible ram on said loader for pivoting said boom arms, a control linkage means including a second extensible ram pivotally connected to said boom arms and said loader; the improvement comprising:

(a) a grab member including a plate having a semicylindrical front face and rear portion,

(b) bracket means mounted on the rear portion,

(c) means pivotally connecting said bracket means to said boom arms,

(d) means pivotally connecting said bracket means to said control linkage means,

(e) at least one grab arm of semi-cylindrical shape pivotally connected to said bracket means,

(f) said plate having a plurality of openings adjacent said bracket means,

(g) a first pair of gripping shoes positioned on said front face,

(h) said gripping shoes having oppossed curved gripping faces conforming generally to said front face,

(i) tab portions on said first shoes projecting through said openings and being removably connected to said bracket means,

(j) a second pair of gripping shoes each having a gripping face oonforming to the shape of said grab arm,

(k) means releasably connecting said second shoes to said grab arm, and

(l) and third extensible ram means connected to said bracket means for pivoting said grab arm.

2. In a tractor loader including a pair of boom arms pivotally mounted on said loader, a load-handling device comprising:

(a) a grab member pivotally mounted on said boom arms, said grab member including plate means for engaging a first load,

(b) grab arm means pivotally mounted on said grab member, said grab arm means including at least one grab arm adapted for engaging said first load,

(0) first shoe means removably mounted on said plate 'means,

(d) second shoe means removably mounted on said grab arm,

(e) said first and second shoe means frictionally gripping a second load when mounted, and said plate means and grab arm gripping said first load when said first and second shoe means are removed.

3. In a tractor loader as defined in claim 2, wherein:

(a) said plate means and said grab arm have first opposed curved gripping faces, and

(b) said first and second shoe means have second opposed curved gripping faces.

4. In a tractor loader including a pair of boom arms pivotally mounted on said loader, a load-handling device comprising:

(a) a grab member pivotally mounted on said boom arms, said grab member including plate means for engaging a first load,

(b) grab arm means pivotally mounted on said grab member, said grab arm means including at least one grab arm adapted for engaging said first load,

(0) first shoe means removably mounted on said plate means,

(d) second shoe means removably mounted on said grab arm,

(e) said first and second shoe means gripping a second load when mounted, and said plate means and grab arm gripping said first load when said first and second shoe means are removed,

(f) said plate means and said grab arm have first opposed curved gripping faces,

(g) said first and second shoe means have second opposed curved gripping faces,

(h) said first gripping faces of said plate means and said grab arm conformed generally to the shape of said first load, and

(i) said gripping faces of said first and said second shoe means conform generally to the shape of said second load.

'5. In a tractor loader including a pair of boom arms pivotally mounted on said loader, a load-handling device comprising:

(a) a grab member pivotally mounted on said boom arms, said grab member including plate means for engaging a first load,

( b) grab arm means pivotally mounted on said grab member, said grab arm means including at least one grab arm adapted for engaging said first load,

(c) first shoe means removably mounted on said plate means,

(d) second shoe means removably mounted on said grab arm,

(e) said first and second shoe means gripping a second load when mounted, and said plate means and grab arm gripping said first load when said first and second shoe means are removed, and

(f) at least one strip of resilient material is affixed at the outer margin of each of said first and second shoe means for contacting said second load.

6. In a tractor loader, a load-handling device comprising:

(a) a boom pivotally connected to said loader,

(b) mounting means on said boom,

(c) a grab member pivotally mounted on said mounting means for engaging a load,

((1) grab arm means pivotally mounted on said grab member for engaging said load,

(e) first ram means to pivot said grab arm means relative to said grab member for gripping said load,

(f) second ram means to pivot said grab member relative to said boom between a forward load engaging position and a maximum roll back position, with the boom mounting means and the grab member sized and position such that said mounting means is positioned directly below the center of said load when the boom is in its highest raised position and the grab member is pivoted to its maximum roll back position,

(g) first shoe means removably mounted on said grab member,

(h) second shoe means removably mounted on said gra'b arm means, and

(i) the first and second shoe means cooperating to frictionally grip another load.

References Cited by the Examiner UNITED STATES PATENTS 2,626,722 1/1953 Talbott 214-653 2,739,009 3/1956 Phillips 214-653 X 2,740,210 4/ 1956 Hamborg 294-106 X 2,752,054 6/ 195 6 Thompson. 3,034,821 5/1962 Hackett et a1. 294-88 3,045,845 7/1962 Hackett et a1. 214- HUGO O. SCHULZ, Primary Examiner. 

1. IN A TRACTOR LOADER INCLUDING A PAIR OF BOOM ARMS, EACH HAVING ONE END PIVOTALLY CONNECTED TO OPPOSITE SIDES OF SAID LOADER, A FIRST EXTENSIBLE RAM ON SAID LOADER FOR PIVOTING SAID BOOM ARMS, A CONTROL LINKAGE MEANS INCLUDING A SECOND EXTENSIBLE RAM PIVOTALLY CONNECTED TO SAID BOOM ARMS AND SAID LOADER; THE IMPROVEMENT COMPRISING: (A) A GRAB MEMBER INCLUDING A PLATE HAVING A SEMICYLINDRICAL FRONT FACE AND REAR PORTION, (B) BRACKET MEANS MOUNTED ON THE REAR PORTION, (C) MEANS PIVOATALLY CONNECTING SAID BRACKET MEANS TO SAID BOOM ARMS, (D) MEANS PIVOTALLY CONNECTING SAID BRACKET MEANS TO SAID CONTROL LINKAGE MEANS, (E) AT LEAST ONE GRAB ARM OF SEMI-CYLINDRICAL SHAPE PIVOTALLY CONNECTED TO SAID BRACKET MEANS, (F) SAID PLATE HAVING A PLURALITY OF OPENINGS ADJACENT SAID BRACKET MEANS, (G) A FIRST PAIR OF GRIPPING SHOES POSITIONED ON SAID FRONT FACE, (H) SAID GRIPPING SHOES HAVING OPPOSSED CURVED GRIPPING FACES CONFORMING GENERALLY TO SAID FRONT FACE, (I) TAB PORTIONS ON SAID FIRST SHOES PROJECTING THROUGH SAID OPENINGS AND BEING REMOVABLY CONNECTED TO SAID BRACKET MEANS, (J) A SECOND PAIR OF GRIPPING SHOES EACH HAVING A GRIPPING FACE CONFORMING TO THE SHAPE OF SAID GRAB ARM, (K) MEANS RELEASABLY CONNECTING SAID SECOND SHOES TO SAID GRAB ARM, AND (L) AND THIRD EXTENSIBLE RAM MEANS CONNECTED TO SAID BRACKET MEANS FOR PIVOTING SAID GRAB ARM. 